1. Field of the Invention
The invention relates to robots used for substrate transport in semiconductor processing.
2. Description of the Related Art
Robots are commonly used in semiconductor processing environments, in order to transport substrates such as wafers to and from storage locations or various processing stations. The highly repetitive nature of the motions involved and the speeds required for high throughput make robots ideal candidates for these tasks. The types of motions of which these types of robots are capable vary. Typically, a robot having a robot body and robot arm extending from the robot body will exhibit angular (θ), radial (R) and Z motions in a cylindrical coordinate system. Angular motion refers to rotation of the robot arm about a primary axis at which it is pivotably coupled to the robot body. Radial motion is extension/retraction motion of the robot arm to and from the primary axis. Z motion is elevation of the robot arm (up-down) with respect to the robot body. Details of operation of such robots are described in U.S. Pat. No. 5,789,890, entitled “ROBOT HAVING MULTIPLE DEGREES OF FREEDOM (Genov et al.), incorporated herein by reference in its entirety.
Issues that are of concern in these types of robots include weight, size, complexity, and range. The present invention seeks to address one or more of these issues, to thereby improve factors such as robot performance, reliability, and throughput, and to increase longevity and reduce costs of robot manufacture and maintenance.